Fuse plug



May 27, 1924 Q. J j@ E. L. OGLE FUSE PLUG Filed Oct. 12 1921 Y M,/// d Q 7 0 Patented May 27, 1924.

UNITED STATESv PATENT OFFICE.

ELMER L. OGLE, OFVCI-IICAGO, ILLINOIS, ASSIGNOR 'I JO FEDERAL ELECTRIC COMPANY, OF CHICAGO, ILLINOIS; A CORPORATION OF ILLINOIS.

FUSE PLUG.

Application filed October 12, 1921.

To all whom it may concern.'

Be it known that I, ELMER L. OGLE, a citizen of the United States, and a resident of Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Fuse Plugs; and I do hereby declare that the following is a full, clear, and exact description thereof, reference'being had to the accompanying drawings, and to letters of reference marked thereon, which form a part of this specification.

This invention relates to improvements in electric fuse plu s and consists of the matters hereinafter escribed and more particularly pointed out in the appended claims.

One of the objects of thek invention is to provide a fuse wherein the fusible element is in the form of a reiill cartridge which may be quickly removed when blown and readily replaced by a new one.

A further object of the invention is to so construct the plug that it will be inoperative if a current conductor other than the particular associated cartridge is inserted into the plug in lieu of said cartridge. Y

Still a further object of the invention is to provide a cartridge holder which can only be inserted into the casing in a certain predetermined manner so that it is impossible to reassemble the plug after a refill `and have an inoperative plug.

These objects of the invention together with the many advantages thereof will more fully appear as I proceed with my specification.

In the drawings:

Fig. 1 is a perspective view of a fuse plug embodying my invention.

Fig. 2 is a vertical central section through the fuse plug on an enlarged scale, the refill cartridge being shown partly in elevation and partly in section.

Fig. 3 is a horizontal section through the fuse plug on the line 3-3of Fig. 2.

Fig. 4 is a perspective view of a refill cartridge holder embodied in my improved fuse lu f p Fgig. 5 is' a fragmentary detail sectional view showing a modified form of my invention. f.

Fig. 6 is a perspective view of 'a modified form of refill cartridge-holder.

Referring now in detail to that embodiment ofthe invention illustrated inthe ac- Serial No. 507,218.

companying drawings, 5 indicates the body of the fuse plug which is made of a suitable insulation material. Said body is made cylindrical in cross section and the end 6 thereof provide a recess 9 in said body near the head,

into which a part 10 of the shell is forced, as shown in Fig. 2.

In the plug body andl opening through one yend thereof is provided a longitudinally extending cylindrical recess 11 in which a cartridge holder 12 snugly fits. Communicating with and opening into one side of the recess 11 is a second longitudinally extending rectangular recess 13 which opens at one end, laterally through the body, `iust beyond the gripping head. Located in the recess 13 is a spring contact member or brush 7 a which is riveted or otherwise secured to the contact shell 7 A part 14 of the recess 11 is restricted in diameter to provide longitudinally extending shoulders 15 and a radial shoulder 16 near the end of the plug body.

The cartridge holder 12 has a tubular body 17 which fits within the recess 14: and a radially flanged head 18 at the outer end which engages the end of the plug body and over laps the flange 8 of the contact shell 7. A part of the body of the cartridge holder is cut away to provide shoulders 19 and 20 which are complementary to and engage the shoulders 15 and 16 of the plug body so as to prevent a relative rotation between the plug body and cartridge holder. Thus, as is apparent, the cartridge holderY can be inserted into the plug body in one manner only and when thus inserted, will turn. with said plug body when the same is threaded into a socket.

The inner end of the holder 12 is reduced in v tridge includes a fusible element 24 having an end 25 which extends to the outside of the cartridge, to provide' the usual tell tale tag. This ta-g has impressed upon it the number for indicating the "vltageat -`which thatparticular cartridge'may besafely used.

As the cartridge shown herein isfully illustratedY and described in my copending application, SQN. 497,888 filed September 2,

i921, the saine Will only be set forth inV general in this instance. In the outerend of the cartridge is a metallic plug 26 to which the fusible element 24- is connected. This plug has a threaded lcentral bore 27 and vthe"tubular body 28 of the cartridgggeis secured'to the plug 26 by Vacap there being `a'longitudinal SlotBO lin one iside .of

the outer endof vthe cartridge to 'receive a pin 3l carried by thephojlder. In-the end i apertureddisc 32 of 'a' thic'lnies's"equa-lfy to screw vhasi'a VhiaatlfBS beyond the Aend vof theV the pitch o-fftheithrea'ds: oni therend of afscrew Bel' carried the helden `This `body -yfhich constitutes the ceiitralfcontact member ofl the fuseplug 'andbyineans of Which the end 38 of the screw finay be `threacled 'through thedisc 32'and into the bore`27 of they plug 26. YAThe discthus acts lto Viholderbutin no ivay interferes With the rotation of the screw. theinner eXtreme end ofthe holderin lineV flattened side 2l thereof, lis provided a notch 36 delining spaced shoulders which form aguide lfor the,v exposed end' l25of the fusible element.'

'Assume that the holder is removed v'fromv thel plug body and it is desired 'to load V'the same With'a vcartridgeV The outer end of the cartridge isinsefrted into 'the '-bore 22 of the holder, vvith the pin 3l VextendingY into the groove() of the, cartridge. d*This correc'tly'v positions the cartridge l in they Vh0lder.

f'The'screW Sbeing siviveled the holder and being in line Withfbofrev 2.7 lin the car;

tridge, may non? bethrea'ded into said bore. rlhis secures t-heouterv end of the cartridge tothe holder, the'pin and groove construction beforeV mentioned preventing" rotation of the cartridge when screwing inthe screiv 34. After this has been done, the exposed end 25 ofthe fusible element 24 is b'entbver and through the notch "B'G'and then `into`eng gagement 'With the flattene'dfpartor face' 121 on the inner Jend 'of the-holder.

' vThe holder is neXt inserted 'into the recess in Vthe "plug body', the engaging Vshoulders l5 and lQbeforef described al'yi'aysinsuring thefcorrect' registration nofthe 4andthe l'shoulders 16` iand' 201 determining thev`- liinit of the insertion. When inserted, the #tell within@ brus 'T l1@ ellis" easily removed and replaced by'a. new one and the parts are so 'arranged that there can be no error" in the"'replacement'.V

No foreign'conductor may be substitutedVV for the particular cartridge Vdesigned for use in the fuse plug and produce an operative device. Thus life and property are pro- .te'cted thereby.

The screw 34- is secured in the holder so as 'to swivel' therein, by the disc 32. This is a simple and eflicient construction.

4In Fig. 5 isillustrated a construction wherein the recess v13" extendsthe full length Y ofthe fuse body 5X, and opens through the end vthereof instead of terminating shortly below the 2l Upon t e associated cartridge'holder l2x (See Figptfl 'provide a lug l2yA which fits Withinand closes the bottomj end of the recessv 13X whenisaidfcartridgev holder has4 been vinserted vinteAV a fuse 'body 5*. "A fuse body Withfa'recess yasfshf'nvn' in Fig. 5 may v'bemore easilyr made because it can be readily virith"dr'avn' from -thef mould."v The lug l2?y on the ,associated holder '12? additionally in-V sur'es correct registry of the parts' 'and makes error in'assembly quite impossible.

' While iifdes'crib'ingmy' invention l have referredV tocertain details of mechanical -construction and arrangementof parts,V Ido not Wish Vto be limited thereto 'ei'zfcept :asfY

pointed outv yin theappended claims. I

2. A Vfuse plug comprising an insulatingf' body having a contact shellnt onefendt-hereof, 'al fuse cartridge holder 'adapted to beinserted into the body from said shell end, a contact linger in the body,-connected tothe isli'ellf, 'said' 'linger --bein'gv adapted 'for enga-ger mentwith the fusible member ofthe can gtridge, and central co'ntactmenib'er Vswiveled i' in'fthe l 'e'ndgef the holder'andadapted to secure thecartridge in the holder.' Y Y '31 f'use' plug fcornprisingfaii insulating -body having acontactshell at one 'end thereof, a fuse cartridge holder adapted to be inserted iiito thebodyfroni said shell end, a contact" finger in the body, connected' to the shell, said finger being adapted for engageA it with thefusibie r11-einher di the eartridge, and ascertain carried by the'holderand tempted-'t be 'threaded inte the-"endff the celt'idge'tt'o "'sere'th'e' saine' "tlieholderi 4. A holder for a fuse cartridge having a threaded opening in one end, said holder comprising a tubular body closed at one end, a screw mounted in the closed end of the body and having a head without said body, and a threaded end within said body and adapted to be screwed into the. threaded hole in the end of the cartridge, to secure the same in the holder, and means in said holder and engaging the screw to permit a free rotative movement and a limited endwise movement of said screw with respect to said holder.

5. A holder for a fuse cartridge having a threaded opening in one end, said holder comprising a tubular body closed at one end, a screw mounted in the closed end of the body and having a head without said body, and a threaded end within said body and adapted to be screwed into the threaded hole in the end of the cartridge, to secure the same in the holder, and a disc in said holder of substantially a thickness equalling the pitch of the threads on the threaded end of the screw and through which said end is screwed, said disc engaging the screw and permitting a free rotative movement thereof and a limited endwise movement of the screw with respect to the, said holder.

6. A holder Jfor a fuse cartridge having a threaded opening in one end, said holder comprising a tubular member having a hole at one end which opens into the interior of the holder, a screw in said hole having an enlarged head without the holder and a threaded end within the holder adapted to be screwed into the threaded opening in the fuse cartridge, said head and threaded end of the screw being connected by a neck of smaller diameter, and a loose disc in said holder through which said threaded end is screwed and thereafter engages saidthreaded end in a manner permitting a free rotative movement of the screw and a limited end wise movement thereof with respect to said holder.

7. A fuse plug comprising, an insulating body having a longitudinal recess which opens through one end thereof, a threaded contact shell on said end of the body, a fuse cartridge holder adapted to be inserted into said recess, sald body and cartridge holder having inter-engaging parts insuring correct insertion of the holder and preventing a relative rotation between the body andthe holder, means carried by the holder for securing the cartridge therein and providing the other contact member for the fuse plug, and a spring contact linger in said body and connected to the shell, said spring Contact linger being automatically engaged by a part of the cartridge when the holder is inserted into the recess.

8. A fuse plug comprising, an insulating body having a central recess which opens through one end of the body and a second recess which communicates with the lirst and opens through the side of the body, a threaded contact shell fixed on said end of the body, a spring contact nger in the second recess and connected to the contact shell, a fuse cartridge holder adapted to be inserted into the first mentioned recess, said holder having a part substantially closing 01T said recess when it is in position in said body, a fuse cartridge having one end of a fusible member arranged outside the holder and engaged by said contact linger and means associated with the exposed end of the holder for securing the cartridge in the holder.

9. A holder for a tell tale tag fuse cartridge comprising a tubular body having a head at one end, and a notch in the other end of the body, said body having a iiattened portion in line, with said notch, and with which the tell tale tag engages after being bent over and passed through the notch, and means carried by the head end of the holder for securing said fuse cartridge therein.

In testimony that I claim the foregoing as my invention, I affix my signature in the presence of two witnesses, this 7th day of October A. D. 1921.

ELMER L. OGLE.

.Witnessesz CLARENCE E. MEHLHOPE, T. H. ALFRnDs. 

